Although it is known that many medical problems of postmenopausal women relate to changes in levels of reproductive hormones, the cost of measuring multiple hormones prevents them from being routinely monitored as a woman passes through her reproductive phases. This results in little understanding of the physiological basis for side effects associated with hormone replacement therapy. Innovation Associates proposes to pursue Phase II development of a fiber optic sensor for simultaneous measurement of estradiol, progesterone, FSH and LH in serum. Use of this instrument in physician's offices will reduce measurement costs while providing, within minutes, results comparable to those obtained from clinical assay. During Phase I, Innovation Associates demonstrated that a fiber optic sensor can assay estradiol in the physiological range of interest using time resolved fluorescence. This will be extended to simultaneous measurement of multiple hormones in Phase II. Time resolution permits fluorescence to be separated from natural serum fluorescence so that assay can be performed on unprocessed serum. Fiber optic sensing makes physical separation of free from bound fluorescence unnecessary. Together these methods provide the basis for development of an instrument offering the speed and simplicity required for physician's office, hospital bedside and field applications. PROPOSED COMMERCIAL APPLICATION: Designed for physicians' offices, hospital bedside, and field situations, a simple low cost fiber optic sensor will have wide application to many hormones, drugs, infectious agents and metabolites. It will give immediate results and has flexibility for measuring substances determined by snap in probes chosen by the physician The first in this family of sensor probes will include reproductive hormones of interest to specialists in obstetrics and gynecology.